code: def ensure_non_nested_foreach(self, f):
      return self._decorate("require_non_nested_foreach", f)
  
imports: import re
  from .exception import MetaflowException
  from .util import all_equal
label_desc: Use image node_id 6 for calling the FlowLinter obj's underlying member method code with example usage: obj.ensure_non_nested_foreach(f) and returns: self